Chemical cycles in the oceanic crust

洋壳中的热液循环在控制世界海洋的组成、为极端生物提供能量和营养以及产生具有重要经济意义的矿藏方面发挥着关键作用。在大洋板块的整个生命周期中，从大洋中脊的形成到俯冲带的地幔循环，岩石圈和海洋之间的热量和质量都在交换。我提出的研究计划的重点是了解是什么推动了这种交换，无论是在高温热液系统活跃的大洋中脊，还是在海底风化占主导地位的离轴地区。在这两个环境中，我们将地质约束与地球化学示踪剂的洞察相结合，以评估哪些环境条件控制化学反应和元素流动性。对于大洋中脊环境，我们将通过研究一种新型深海钻机回收的钻芯来研究海水进入下部大洋地壳的条件和后果。我们还将通过海王星网络分析胡安德富卡海脊奋进段活动热液系统记录高温流体性质的仪器的实时数据流。我们在离轴环境中的重点是通过探索与海水化学和气候的联系来促进我们对海底风化如何响应外部强迫的理解。我们将利用广泛的国际钻探方案和盆地规模数据集的核心集合，对海底风化产品进行深入研究，以开发预测模型，评估地壳年龄与气候状态和海水化学对海底风化地球化学通量的相对重要性。

Hydrothermal circulation in the oceanic crust plays a critical role in controlling the compositions of the world's oceans, provides energy and nutrients for extremophile organisms and generates ore deposits of economic importance. Heat and mass are exchanged between the lithosphere and oceans throughout the lifecycle of an ocean plate, from its creation at mid-ocean ridges to its recycling back into the mantle at subduction zones. My proposed research program focuses on understanding what drives this exchange, both at mid-ocean ridges where high temperature hydrothermal systems are active and in the off-axis where seafloor weathering dominates. In both environments, we integrate geological constraints with insights from geochemical tracers to assess what environmental conditions control chemical reactions and element mobility. For the mid-ocean ridge setting, we will examine the conditions and consequences of seawater ingress into the lower ocean crust by studying drill cores recovered by a novel deep-sea drill. We will also analyze the real-time data stream from instruments recording high temperature fluid properties from active hydrothermal systems at the Endeavour segment of the Juan de Fuca Ridge through the NEPTUNE network. Our focus in the off-axis environment is to advance our understanding of how seafloor weathering responds to external forcing by exploring linkages with seawater chemistry and climate. We will conduct an in depth study of the products of seafloor weathering using the extensive core collection of international drilling programs and basin-scale datasets to develop predictive models that assess the relative importance of crustal age versus climate state and seawater chemistry for seafloor weathering geochemical fluxes.